PHILADELPHIA -- As with almost any first-round pick, rookie outside linebacker Marcus Smith is expected to have an immediate impact on the Eagles' defense.

That impact is going to be hard to make, however, running with the third string -- behind the best linebacker on the team.

Smith spent nearly all of the Eagles' practice on Thursday with the third-team defense, backing up last year's starter, Connor Barwin, and newly signed Bryan Braman at the left outside linebacker position.

That Smith isn't on the starting unit yet is not surprising, because he is expected to backup last year's starter -- linebacker Trent Cole -- to start the season. That Smith was on the third team on Barwin's side, however, was noteworthy.

"I might learn the 'predator' along the way, but right now I'm just learning the 'jack'," Smith said after practice. "They want me to master that one position."

The 'predator' on the Eagles' defense is currently Cole, who spent nearly all of his snaps last season rushing the passer -- a role for which he is best-suited. Although Smith has the ability to drop back into coverage and rush the passer, it was believed he was drafted to take over for Cole, given how well Barwin played last season.

The Eages have placed Smith behind Barwin to have him learn the more complex position first, and then will have him to rush the passer when needed. Smith learning Barwin's position also allows the Eagles to move Barwin to Cole's spot at times, a move that would give Barwin more chances to rush the passer while Smith drops back into coverage.

"They are pretty much identical. If I'm going, the other guy is dropping," Smith said.

Still, placing Smith behind Barwin does not appear to be a decision that will get the rookie on the field quicker -- and certainly won't help fans feel better about a pick they have been questioning.